粒子群の充填・排出特性に及ぼす粒子形状の影響

抄録

To investigate the shape effect of particles on their static and dynamic characteristics, the void fraction ε of a packing bed in a cylinder and the discharge rate V_o of particles through a circular orifice were measured by using many kinds of materials differing in particle shape, size d_p and density ρ.
The particle shapes for each material were evaluated by a pair of shape indices φ and ζ. These indices were defined as a measure of circularity and smoothness of a particle profile in our previous paper. The experimental results were discussed using the multiple regression analysis.
The following experimental results were obtained: (1) The void fraction ε depended on the microscopic shape index ζ of each particle rather than on the macroscopic one φ.: (2) The term V_o/(√gd_p^2.5), which represents the discharge characteristics of particles through an orifice, could be correlated as a function of ζ^5.94 and (D_o/d_p)^2.8, regardless of φ.
As a result, it was confirmed that the static and dynamic behavior of particles was closely connected with the surface roughness of each particle.